Quick-release tube clamp for modular lower limb prosthetic systems and method therefor

ABSTRACT

A quick-release tube clamp and method therefor for locking and releasing a prosthetic pylon/foot component from the socket. The quick-release tube clamp includes a tubular portion, an annular socket portion, and a clamp portion. The tubular portion has a formed slot along a longitudinal length of the tubular portion. The tubular portion forms a cylindrical opening with an inner diameter slightly larger than the outer diameter of the tubular pylon. The annular socket at the upper end of the tubular portion attaches to the socket of the modular lower limb prosthetic system. The clamp portion is located near the lower end of the tubular portion and firmly locks the tubular portion around the tubular pylon when the tubular pylon is inserted into the tubular position and provides a releasing position for removal of the tubular pylon.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a mechanism for releasing a prostheticpylon/foot component from a lower limb prosthetic socket and, moreparticularly, to providing a quick-release for such a mechanism andmethod therefor.

2. Discussion of the Background

With the introduction of modular prosthetics in the mid-1990's, a numberof conventional mechanisms have been designed to connect and to releasea prosthetic pylon/foot component from the prosthetic socket of a user.In the lower limb prosthesis industry, a conventional link-plate isrigidly attached to the base of the socket, the link-plate typically hasa downwardly extending pyramidal boss. A connector with an annularsocket usually having four set screws couples to the pyramidal boss. Thefour set screws are adjusted and tightened, usually by a trainedprofessional, to provide proper fitting for the prosthetic pylon/footcomponent. This is found, for example, in U.S. Pat. Nos. 3,659,294 and6,458,163.

One prior approach for coupling to the pyramidal boss of the link-plateis set forth in U.S. Pat. No. 5,571,211 which provides a tubularadapter. The tubular adapter has the annular socket with four set screwsfor coupling to the pyramidal boss, a connecting sleeve with a formedaxial slot between two outer tabs, and a plastic clamping cuff placed inan annular groove of the sleeve. When the tubular pylon of theprosthetic pylon/foot component is inserted in the sleeve, a clampingbolt engaging the two outer tabs is tightened to cause the plastic clampto press against the inserted tubular pylon. The clamping bolt, outertabs and plastic clamp provide a release mechanism requiring a separatetool for tightening and releasing. The tool is carried by the user.

A continuing need exists to improve such release mechanisms. Forexample, the simple act of putting on and taking off pants underscoresthe need for a lower limb prosthetic system wherein the pylon/footcomponent can be quickly removed so that the pants can be pulled overthe socket and then reattaching the pylon/foot component to the socketthrough the leg of the pants. For active persons, a further need existsto quickly remove the prosthetic pylon/foot component to either attach anew prosthetic pylon/foot component (for the desired activity) or toadjust the present prosthetic pylon/foot component (such as for toe-inor toe-out). For example, users may require different pylon/footcomponents based on the activity, such as different feet with differentshoes, wet-legs, running legs, climbing legs, riding legs, etc. By wayof further example, when a user continually walks or walks uphill, theresidual limb may tire from being at the same angle and/or pressure. Thetoe-in and toe-out can be adjusted to change the angle and/or pressure.Many other situations present themselves where releasing andremoving/adjusting the pylon/foot component is advantageous to a user:sitting for extended periods of time, riding in a car, crawling, takinga shower, etc.

In situations where the pylon/foot component is frequently removed, afurther need exists to provide a release mechanism that is durable. Forexample, in a situation where a prosthetic lower limb is reattached tothe socket and a plastic part strips or fails, the user may be in asituation (such as out of doors, at a mall, etc.) where a replacementpart is not available and the prosthetic lower limb is unable to bereattached. This presents a substantial inconvenience to the user. Someusers also carry replacement parts with them in the event a failureoccurs. A further need exists to provide an attachment mechanism whichdoes not require the use of a special tool that would have to be alsocarried with the user.

The, following patents provide release mechanisms not requiring aseparate tool.

U.S. Pat. No. 4,564,365 discloses a quick change mechanism for a limbprosthesis requiring the use of two opposing cam latches located onopposite sides of a tubular member that allows the pylon/foot componentto be released from the socket portion. This occurs by moving convexarches into and out of a recessed cylindrical area. A fail safe retainerclip engages the ends of the cam latches to prevent accidental release.

U.S. Pat. No. 4,938,775 recognized that the above '365 patent provided acomplex design that was not strong enough for athletic activities andwould require substantial modification for use with existing artificiallegs. The '775 patent provides a first attaching member permanentlyattached to the lower end of the socket to releasably retain a secondmember on the removable support prosthesis. A handle is moved to engageand clamp the two mating members together. When the handle is raised,the attaching members release and the prosthesis can be removed. The'775 patent requires each different prosthetic pylon/foot component tohave an attaching plate and a bearing attached to the upper end of thepylon. In use, the user must align and then seat the two attachingmembers together.

U.S. Pat. Nos. 5,928,290; 6,093,210; 6,235,062; and 6,402,789 provide afastening device for a prosthesis to permit withdrawal of thecylindrical insert into an inclined washer fastening device.

British patent provisional specification No. 155,917 utilizes a slidingsleeve to lock a steel ball in a groove so that a prosthesis can beremoved without use of tools.

In an entirely different technological area, quick-release mechanismsare conventionally used. For example, for bicycle seats, U.S. Pat. Nos.6,581,492; 6,305,869; and 6,318,741 all relate to quick-releasemechanisms. In another example for rotary die cutting, U.S. Pat. No.4,054,394 discloses a curved lever arm shaped to conform to the contourof the circular head along with a spring clip to hold the lever in placeto prevent accidental release.

A continuing need exists for a quick-release mechanism and methodtherefor for locking and releasing a prosthetic pylon/foot componentfrom the socket without the use of a special tool. A further need existsfor a quick-release mechanism which is simply constructed with few partsand which is durable for an active user. A need exists for aquick-release mechanism that does not require any alignment and seatingof the locking mechanism, does not rotate when locked, and that does notrequire modification of the conventional prosthesis pylon of thepylon/foot component.

SUMMARY OF THE INVENTION

The present invention solves the afore-said needs by providing aquick-release mechanism and method therefor for locking and releasing aprosthetic pylon/foot component from the socket without the use of aspecial tool. The present invention further provides a quick-releasemechanism constructed of only a few parts, all of which are durable foran active user. The present invention provides a quick-release mechanismthat does not require any alignment in seating of the locking mechanism,does not rotate when in the locking position, and does not requiremodification of conventional pylon/foot components.

The quick-release tube clamp of the present invention includes a tubularportion, an annular socket portion, and a clamp portion.

The tubular portion has at least one formed slot along a longitudinallength of the tubular portion, and the tubular portion forms acylindrical opening with an inner diameter slightly larger than theouter diameter of the tubular pylon.

The annular socket at the upper end of the tubular portion attaches tothe socket of the modular lower limb prosthetic system.

The clamp portion is located near the lower end of the tubular portionfirmly locks the tubular portion around the tubular pylon when thetubular pylon is inserted into the tubular position and provides areleasing position for removal of the tubular pylon. The clamp portionincludes a pair of opposing tabs located on opposing sides of the formedslot and a handle. The handle has a cam at one end and is curved tofollow the shape of the tubular portion. When the handle is moved intothe locking position, the cam operates on the pair of opposing tabs tolock the tubular portion around the inserted tubular pylon by reducingthe width of the formed slot.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 sets forth a side view of the modular lower limb prostheticsystem of the present invention.

FIG. 2 sets forth the modular lower limb prosthetic system of FIG. 1showing the prior art socket and the prior art pylon/foot component, aswell as the quick-release tube clamp of the present invention takenapart.

FIG. 3 sets forth a perspective view of the quick-release tube clamp ofthe present invention in a locked position.

FIG. 4 is a perspective view of the quick-release tube clamp of thepresent invention in the unlocked or released position.

FIG. 5 is a cross-sectional view along lines 5-5 of FIG. 3.

FIG. 6 is a cross-sectional view along lines 6-6 of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, a modular lower limb prosthetic system 10 is shown to includea conventional socket 20 and a conventional pylon/foot component 30. Thequick-release tube clamp 40 of the present invention is shown firmlyconnecting the pylon/foot component 30 to the socket 20.

In FIG. 2, the quick-release tube clamp 40 of the present invention isshown released from the socket 20 and released from the pylon/footcomponent 30. The conventional pylon/foot component 30 also has aconventional tubular pylon 50 and a conventional prosthetic foot 60. Thetubular pylon 50 is connected with a conventional connector 70 to theprosthetic foot 60. It is to be expressly understood that the pylon/footcomponent 30 is conventional, as is the tubular pylon 50, the prostheticfoot 60, and the connector 70. Connector 70 can be a complex connectoror simply using epoxy to glue the tubular pylon 50 to the foot 60. Thepresent invention is not limited to the pylon/foot component 30 and anyof a number of different such components 30 could be utilized with thequick-release tube clamp 40 of the present invention. The fact that thepylon/foot component 30 is conventional is also shown as “prior art” inFIG. 2.

Likewise, socket 20 is conventional as is the link-plate 80 having adownwardly extending pyramidal boss 90. The fact that the socket 20,link-plate 80, and pyramidal boss 90 are conventional is shown in FIG. 2as “prior art.”

In FIGS. 3 and 4, the quick-release tube clamp 40 of the presentinvention is shown locked in place (FIG. 3) and released (FIG. 4). Thequick-release tube clamp 40 has a handle 300 which pivots about a pivotpin 310. The quick-release tube clamp 40 also has a tube portion 320 andan annular socket portion 330. The handle 300 engages a clamp portion340 of the quick-release tube clamp 40. In one embodiment, the portions320, 330 and 340 are integral. In other embodiments, the portions 320,330 and/or 340 may constitute separate structures. The clamp portion 340also includes two raised opposing tabs 350A and 350B. A slot 360 isformed in the tubular portion 320 and between the opposing tabs 350A and350B of the clamp portion 340. The clamping portion 340 also has aknurled thumb nut 370.

The annular socket portion 330 has four set screws disposed there aroundwhich are used to connect to the pyramidal boss 90 on the link-plate 80affixed to the socket 20. Again, it is to be expressly understood thatthe use of the four set screws 380 and the provision of the annularsocket 330 as it interconnects to the pyramidal boss 90 is conventional.A trained professional will adjust the set screws 380 to provide aproper fit to the user of the modular lower limb prosthetic pylon/footcomponent 10. It is to be expressly understood that the teachings of thepresent invention are not limited to the use of four set screws or theshape of the annular socket portion 330 and that any suitable number ofset screws 380, shape of the annular socket 330 could be utilized underthe present invention.

In operation, the user of the quick-release tube clamp 40 of the presentinvention uses thumb nut 370 for setting how tight the quick-releasetube clamp 40 should engage the tubular pylon 50. The user of thequick-release tube clamp 40 inserts and locks (FIG. 1) or releases (FIG.2) the tubular pylon 50 of the pylon/foot component 30 from thequick-release tube clamp 40 of the present invention.

As shown in FIG. 3, the handle 300 is in a locked position around thetubular portion 320 so that a narrower distance of 400 is achievedbetween opposing tabs 350A and 350B as shown by arrows 402. When thehandle 300 is released in the direction of arrow 404, as shown in FIG.4, a distance of 410 between the opposing tabs 350A and 350B is obtainedas shown by arrows 406. The formed slot 360 acts mechanically as aspring. The handle 300 moving into the locked position (FIG. 5) uses thecam 620 to act against the spring and narrow the width of the slot 360to 400. When the handle is moved into the release position (FIG. 6), thecam 620 releases and the slot 360 returns to its release width 410. Itis to be expressly understood that the distances 400 and 410 are shownillustrated to be wider than found in actual use so that the teachingsof the present invention can be appreciated. It is to be expresslyunderstood that the distance 400 can be quite minimal including with theopposing tabs 350A and 350B actually touching or abutting each other.The formed slot is a desired longitudinal length in the tubular portionand is open at the lower end as shown.

It is appreciated that the quick-release tube clamp 40 of the presentinvention enables the user to simply move the handle 300 in thedirection of arrow 404 to release the tubular pylon 50. Only onemovement is required for release. When the quick-release tube clamp 40of the present invention is locked in position as shown in FIG. 3, theuser simply takes a finger and grips outwardly raised portion 420 of thehandle 300 to move the handle 300 in the direction of arrow 404. In onemovement of the handle 300 to the fully opened position as shown in FIG.4, the user of the present invention can quickly remove the pylon foot50 in the direction of arrow 408 (FIG. 4) from the quick-release tubeclamp 40 of the present invention.

As shown in FIGS. 3 and 4, the clamping portion 340 is located at thelower end of the tubular portion 320 and the annular socket 330 islocated at the upper end. The terms “upper end” and “lower end” arerelative to the direction shown in FIGS. 1 and 2 with respect to thesocket 20 and the foot 60, respectively. The annular socket portion 330is at the upper end of the tube clamp 40 and the clamping portion 340,in one embodiment, is at the lower end of the tube clamp 40. In anotherembodiment, the clamping portion 340 is offset from the lower end sothat the tubular portion 320 may extend downwardly from the clampingportion 340. Use of the term “near the lower end” of the tube clamp 40shall mean at or offset above the lower end of the tube clamp 40.

In FIGS. 5 and 6, cross-sectional views of the quick-release tube clamp40 of the present invention are shown corresponding to the lockedposition shown in FIG. 3 and to the released position shown in FIG. 4,respectively. The tube clamp 40 has a formed cylindrical opening 500having an inside diameter 210 slightly greater than the outside diameter200 (FIG. 2). It is to be understood that the outside configuration ofthe tubular portion 320 in one embodiment is cylindrical, but that anysuitable configuration could be utilized such as, for example,multi-sided, partially cylindrical and partially multi-sided, etc.

In FIGS. 5 and 6, the quick-release tube clamp 40 of the presentinvention is shown in greater detail. In FIG. 5, the handle 300 in thelocked position terminates in slightly raised end 420. As shown in FIG.5, raised end 420 is raised from the tubular portion 320 to enable thefinger of the user to grip end 420 and to lift and move the handle 300in the direction of arrow 404. However, in the locked position as shownin FIG. 5, the handle 300 is, in one embodiment, long enough to extendover 45° from the diameter 503 of the tubular portion 320 through theformed slot 360 (as shown by arrow 502). In this embodiment (i.e.,distance 502 is greater than 45%), if anything catches on the raised end420, accidental release is less likely to happen as the handle 300 ismore tightly coupled to the tubular body 320. This is one embodiment ofthe present invention. In this embodiment, the handle 300 is curved toabut the curved surface of the tubular portion 320 in the region shownas 510, at least including the area shown by arrow 502. In otherembodiments where the tubular portion 320 is multi-sided, the interiorside 302 of the handle 300 can have a mating multi-sided surface. Thisabutment region 510 provides an area of firm engagement of the handle300 with the tubular portion 320. Raised end 420 is designed to beminimal so as to prevent it from catching on something, yet convenientfor a user to grip with a finger so that accidental release of thehandle 300 from the tubular body 320 in the direction of arrow 404 doesnot occur. In other embodiments of the quick-release tube clamp 40 ofthe present invention, the handle 300 can be of any desirable length. Inother embodiments of the present invention, the raised end 420 may takeon different shapes and configurations. In other embodiments of thepresent invention, a separate latching mechanism, not shown, could beutilized to engage the handle 300 so as to further lock the handle 300to the tubular body 320 so as to prevent accidental release.

In FIGS. 5 and 6, the opposing tabs 350A and 350B have formed holes 520Aand 520B for receipt of a bolt 530. One end of the bolt 530 has a loop540 for receiving the pin 310 and the other end of the bolt 530 isthreaded 550 and threadly engages the thumb nut 370. The thumb nut 370has a portion 560 that sets the thumb nut knurled portion 570 slightlyaway from opposing tab 350B. The thumb nut 560, in one embodiment, hasan internal nylon insert 372 that engages the threads 550 of the bolt530 so as to prevent the thumb nut 370 from loosening on its own afterbeing adjusted by the user to a desired tightness. In other embodimentsof the present invention, the thumb nut 370 could engage a lock washer,not shown, to accomplish the same task. Other embodiments of the thumbnut 570 include any mechanism that allows selective adjustment by theuser of the thumb nut 370 for desired tightness of the quick-release toclamp 40 of the present invention against the tubular pylon 50 and tomaintain the desired tightness.

Also shown in FIGS. 5 and 6, in one embodiment, is a camming cup 600having a camming nylon insert 610. The insert 610 provides a “low wear”point for the cam 620 to operate on. In other embodiments of the presentinvention, such a nylon insert is not used. The handle 300 at the endconnected to the pin 310 has a cam surface 620. In FIG. 5, when thehandle 300 is locked, the cam surface 620 forcibly abuts against thenylon insert 610 in the camming cup 600 to move tabs 350A and 350Btogether to obtain distance 400 when the handle is locked as shown inFIG. 5. This is shown by arrow 630 in FIG. 5. When the handle 300 isfully released, the camming surface 620 is removed and the lock is inthe fully released position as shown by arrow 640. The camming surface620 is found on each of the opposing ends 440A and 440B of the handle300. The loop 540 is disposed between opposing ends 440A and 440B. Thetension spring 690 is designed to hold the camming cup 600 in placeagainst the handle 300. In other embodiments of the present invention,the tension spring 690 is not used. In other embodiments of the presentinvention, the camming cup 600 is not used.

As shown in FIG. 6, in the fully released position, a space 650 nowexists between the outer surface of the tubular pylon 50 and the innersurface of the tubular clamp portion 320 so that the user can easilyremove the pylon/foot component 30 from the quick-release tube clamp 40of the present invention in the direction of arrow 408 (FIG. 4).

In FIGS. 3 through 6, one embodiment of the quick-release tube clamp 40of the present invention has been shown. In other embodiments, theopposing tabs 350A and 350B can be designed closer to the tubular body320 embodying more curved surfaces so as not to jut out as far (as shownin these figures) from the tubular body portion 320. The quick-releasetube clamp 40 of the present invention is not limited to the precisemechanical design shown in FIGS. 3 through 6. Any other mechanicalembodiment for moving opposing tabs 350A and 350B together under actionfrom a single lever moving in the direction of arrow 404 could beutilized under the teachings of the present invention.

Under the method of the present invention, and with reference to FIG. 2,the tube clamp 40 of the present invention is in the released positionas shown in FIGS. 2, 4 and 6. The user inserts the tubular pylon 50 intothe tubular portion 320 as shown in FIG. 6. At this point in the method,the inside diameter of the tubular portion is slightly greater than theoutside diameter of the pylon 50 to leave a space 650. The userpositions the foot 60 for proper toe-in/toe-out. The user then moves thehandle 300 in a direction of arrow 404 to lock the tubular portion 320about the pylon 50 as fully described above. The locking position isshown in FIGS. 1, 3 and 5. The above method operates in reverse torelease the pylon 50 from the tube clamp 40 of the present invention.

The above disclosure sets forth a number of embodiments of the presentinvention. Those skilled in this art will however appreciate that otherarrangements or embodiments, not precisely set forth, could be practicedunder the teachings of the present invention.

1. A quick-release tube clamp in a modular lower limb prosthetic systemfor connecting a pylon/foot component to a socket, said pylon/footcomponent having a tubular pylon with an outer diameter, saidquick-release tube clamp comprising: a tubular portion, said tubularportion having at least one formed slot along a longitudinal length ofsaid tubular portion, said tubular portion having a formed cylindricalopening with an inner diameter slightly larger than said outer diameterof said tubular pylon, an annular socket portion at the upper end of thetubular portion for attaching to the socket, a clamp portion near thelower end of said tubular portion, said clamp portion locking saidtubular portion around said tubular pylon in a locking position whensaid tubular pylon is inserted into said tubular portion, said clampportion releasing said tubular portion from said tubular pylon, saidclamp portion comprising: a pair of opposing tabs located on oppositesides of said formed slot, a handle, said handle having a cam at oneend, said handle curved to follow the shape of said tubular portion,said cam operative in a lock position on said pair of opposing tabs forholding said pair of opposing tabs in said locking position by reducingthe width of said formed slot.
 2. The quick-release tube clamp of claim1 wherein said clamp portion is at the lower end of said tubularportion.
 3. The quick-release tube clamp of claim 1 wherein said clampportion is offset from the lower end of said tubular portion.
 4. Thequick-release tube clamp of claim 1 wherein said clamp portion furthercomprises: a thumb nut interconnected to a bolt, said bolt operativelyconnected to said handle, said thumb nut abutting one of said opposingtabs to provide adjustment to the width of said formed slot when saidhandle is operated in said locking position.
 5. The quick-release tubeclamp of claim 4 wherein said thumb nut has an internal nylon insert forholding said thumb nut to said bolt after adjustment.
 6. Thequick-release tube clamp of claim 1 wherein said clamp portion furthercomprises: a camming cup disposed between one of said opposing tabs andsaid cam.
 7. The quick-release tube clamp of claim 6 wherein the cammingcup further comprises: a nylon insert to provide a low wear point whensaid cam abuts against said camming cup to operate said quick-releasetube clamp into said locking position.
 8. The quick-release tube clampof claim 1 wherein said handle terminates in a raised end, opposite tothe end having said cam.
 9. The quick-release tube clamp of claim 1wherein said handle has sufficient length to curve around said tubularportion so as to extend at least 45° from the diameter of the tubularportion through the formed slot, said handle having an interior surfaceabutting against the outer surface of the tubular portion at least insaid 45° region.
 10. A quick-release tube clamp in a modular lower limbprosthetic system for connecting a pylon/foot component to a socket,said pylon/foot component having a tubular pylon with an outer diameter,said quick-release tube clamp comprising: a tubular portion, saidtubular portion having a formed slot along a longitudinal length of saidtubular portion, said tubular portion having a formed cylindricalopening with an inner diameter slightly larger than said outer diameterof said tubular pylon, an annular socket portion at the upper end of thetubular portion for attaching to the socket, a clamp portion near thelower end of said tubular portion, said clamp portion locking saidtubular portion around said tubular pylon in a locking position whensaid tubular pylon is inserted into said tubular portion, said clampportion releasing said tubular portion from said tubular pylon, saidclamp portion comprising: a pair of opposing tabs located on oppositesides of said formed slot, a handle, said handle having a cam at oneend, said handle curved to follow the shape of said tubular portion,said cam operative in a lock position on said pair of opposing tabs forholding said pair of opposing tabs in said locking position by reducingthe width of said formed slot, said handle terminating in a raised end,opposite to the end having said cam, said handle having a sufficientlength to curve around said tubular portion so as to extend at least 45°from the diameter of the tubular portion through the formed slot, saidhandle having an interior surface abutting against the outer surface ofthe tubular portion at least in said 45° region.
 11. The quick-releasetube clamp of claim 10 wherein said clamp portion is at the lower end ofsaid tubular portion.
 12. The quick-release tube clamp of claim 10wherein said clamp portion is offset from the lower end of said tubularportion.
 13. The quick-release tube clamp of claim 12 wherein said thumbnut has an internal nylon insert for holding said thumb nut to said boltafter adjustment.
 14. The quick-release tube clamp of claim 10 whereinsaid clamp portion further comprises: a camming cup disposed between oneof said opposing tabs and said cam.
 15. The quick-release tube clamp ofclaim 14 wherein the camming cup further comprises: a nylon insert toprovide a low wear point when said cam abuts against said camming cup tooperate said quick-release tube clamp into said locking position.
 16. Aquick-release method for releasing a prosthetic pylon/foot componentinserted in a tube clamp, said tube clamp connected to a socket, saidmethod comprising: moving a single lever on the tube clamp from a lockedposition to a released position, increasing the width of a formed slotin said tube clamp as a cam on said single lever is operated in responseto moving the single level from said locked position to said unlockedposition, removing the prosthetic pylon/foot component from the tubeclamp when the single lever is in the released position.